Expandible core for driving molds for concrete piles



EXPANDIBLE CORE FOR DRIVING MOLDS FOR'VCONCRETE FILES Filed Sept. 29, 1949 W. H. COB] Jan. 13, 1953 5 Sheets-Sheet l INVENTOR. 5 W405i /1 005/ 770/? NEV W. H. COB] EXPANDIBLE com: FOR DRIVING MOLDS FOR'CONCRETE FILES Filed Sept. 29, 1949 3 Sheets-Sheet 2 INVENTOR. M17512 /1. 05/

ATTORNEY Jan. 13, 1953 EXPANDIBLE CORE FOR DRIVING MOLDS FOR CONCRETE PILES Filed Sept. 29, 1949 3 Sheets-Sheet 3 INVENTOR. i VA! m? h. 605/ TTOR/VEV Patented Jan. 13, 1953 EXPANDIBLE CORE FOR DRIVING MOLDS. FOR CONCRETE FILES Walter H. Gobi, New York, N. Y.

Application. September 29, 1949;. Scrial No. 118,520

11 Claims.

This .is-an improvement. on the. construction of my former Patent 2,313,625 dated March. 9, 1943.

According to my invention a sheet metal shell of suitable cross-section is provided witha. shoe or tip secured to its. lower end. This shoe is driven by blows applied to a number of longitudihal, thrust bars which engage the shoe. directly or indirectly and carry expandible plates shaped to engage the inner wall of the shell. These bars and the side plates are pressed outwardly by a centrally disposed elastic container, pneumati cally expanded, which container transmits its pressure by a flexible wrapper of non-metallic fabric. These side plates are secured to the thrust bars in a practically operable manner and provide a substantial frictional drag on the shell to supplement a direct thrust against the terminal shoe.

Fig. 1 is a side elevation and partial section of the upper end of a. core for driving a mold for a concrete pile, involving my invention.

Fig. 2 is a similar view of the lower end of a core.

Fig. 3 is a fragmentary section. of the upper end of the expanding member on the plane of the line 33 of Fig. 1.

Fig. 4. is across-sectional view of the lower end of the expanding member on the plane of the line 4-4 of Fig. 2.

Fig. 5 is a horizontal sectionof the core taken on the plane of the line 5-5 of Fig. 2 in the collapsed or contracted condition.

Fig. 6 is a similar section on the plane of the line. 6--6 of Fig. 2 with the core expanded.

Fig. 7 is a cross section of one of the driving bars with a segmental diaphragm attached.

Fig. 8 is a cross section of one of. the outercontact plates.

Fig. 9 is a cross. section; of. one of the driving bars with a contact plate, attached.

Fig. 10 is a longitudinal section of a driving baron the plane. of the line l-I0 of Fig. 9.

Fig. 11 is a cross section on the plane. of the line lI.l-l of Fig. 1.

The shell I is of tubularform and. may have helical ribs. At the lower end a tip or shoe 2 is welded to it around the rim 3. The shape of the tip and the abutment 4. is immaterial to the present invention.

The thrust bars 5, are of steel and may be continuous from top to bottomof the core. Preferably there should be four oftl'reseangle bars. At the top an anvil 6 is provided to receive the blow of the driving mechanism. The shaftv l is supported by the anvil and has a number of flanges or wings 3, 8. Links 9,, 9 are hinged at HI. (0 to these wings and connected'by hinge bolts II, II to the. angle bars. The anvil B: has

lugs 6 by which the anvil may be raised. When the anvil is raised the weight of the angle bars 2. tends to cause them to swing inwardly about the hinge pins I0, I I].

The centering member I2 at the lower end is secured in the abutment 4 and has side flanges or wings l3, '13 which are connected to the angle bars by links l4, I4 hinged. to the wings at [5 and hinged to angle bars at It so that when the angle bars are raised they will swing inwardly. Longitudinally extendingv contact plates l'l', H are secured to the angle bars by special means. A spreader bar I8 is welded at H) at each end to the inner wall of. the contact. plate ll- The bolt 20 connects the spreader bar with the angle bar for which purpose asquare nut 2| is Welded at its edges 22, 22 to the. flanges. of the thrust bar 5 (see Fig. 9).

This bolt 20 is inserted through the spreader bar and has a head 23 by which it may be turned to draw the spreader bar so that its ends are centered between the. enclosed angle of the thrust bar. To enable the parts to be assembled, the plate I! is provided with an opening 24. to permit the bolt 20 to be inserted.

At intervals along the length of each of the thrust bars 5 I provide diaphragm plates 25 which are welded at 26 to the inner walls of the bars.

The interval between adjacent diaphragm plates is. not. critical. I have found a distance of four feet (4') to be satisfactory. This means that the contact plate IT, I! will be approximately four feet long between the diaphragm plates 25. These contact platesv will be connected as above described tov theangle bars at intervals of approximately one foot so that there would be three connections for each contact plate.

At intervals along the length of. the thrust bars I provide tie bolts 21 whichconnect parallel flanges as illustrated in Fig, 6. Thesebolts limit the lateral expansion of the thrust bars.

The respectivethrust bars are normally biased radially toward each other by means of. tie. rods 28 and. springs 29, 29 as shown in Fig. '5.

As in. my former patent I employ an elastic container 30 which. is supplied with pressure fluid throng-ha coupling 3| and hose 32 as shown in Figs. 1 and 3. This connection furnishes a fixed relation to. a flange of onev of the thrust bars and a flexible connection. to the container through the hose 32. Thehose 32. is connected; to the: container 30 by a bushing 33'... The lower end of the container is closed by a. similar bushing 34. The latter, however, is closed by a screw bolt 35.

Between the elastic container and. the. thrust bars; is arranged a transmitting member consisting of'a wrapper formed of segments 36 having,

flanges 31. These flanges are clamped together by plates 38 and bolts 39. These wrapper seg- 3 ments 36 are interposed between the elastic con tainer 30 and the contact area of the thrust bars so that when the container is expanded the wrapper elements change shape as shown by the change from the form of Fig. 5 to the form of Fig. 6. This requires that the wrapper segments must be not only flexible but somewhat resilient. Due to the resilience of wrapper 3B, and as illustrated in Figure 6, inflation of container 30 will stretch wrapper 36 slightly, unless the diameter of the shell being driven prevents the stretching. Consequently, different shells whose diameters vary by as much as three eighths of an inch can be driven by the same core through the use of the resilient wrapper 36. They are subjected to serious stresses in operation and I have found that they are most eflicient if made of a laminated fabric composed of a number of layers of woven nylon with layers of resilient rubber between the nylon layers and on the inner and outer surfaces.

The bushings 33 and 34 are held in place by the straps 33 and 34 which connect opposite clamp plates 38, 38 as shown in Figs. 1 and 2.

At intervals along the length of the plates 38, 38 I provide extensions 46 which are located close to the tie bolts 21 as shown in Figs. 1 and 2 so that when the thrust bars are raised-or lowered the clamp plates 38, 38 and the container will be sure to move with them.

In view of the extreme stresses set up when driving such a core it is essential that there be a very substantial frictional contact between the contact plates [1, l1 and the inner wall of the shell and for this purpose I provide the contact plates with roughened surface l1. This surface may be formed in various ways.

I claim:

1. A driving core for a metallic shell comprising a number of spaced thrust bars, outwardly extending contact plates carried by said bars, an elastic expandible container extending longitudinally between said thrust bars, tiebolts connecting adjacent thrust bars at intervals, and means for transmitting thrust from said bars to said container, said means consisting of plates extending outwardly fromsaid container and engaging said tie bolts.

2. A driving core including longitudinal thrust bars, contact plates projecting circumferentially about said bars, tie bolts connecting adjacent bars, expandible means extending longitudinally between said bars, a hose nipple carried by one of said bars, and a flexible hose operatively connecting said nipple and said expandible means.

3. In an expandible driving core for a tubular shell, the combination of longitudinal thrust bars having outwardly diverging flanges, a row of outer contact plates carried by each bar, each plate having a spreader bar connecting its longitudinal edges and means for drawing each spreader bar and its attached contact plate against the outer edge of the respective angle bars.

4. In an expandible driving core for a tubular shell, the combination of longitudinal thrust bars having outwardly diverging flanges, a row of outer contact plates carried by each bar, each plate having a spreader bar connecting its longitudinal edges and means for drawing each spreader bar and its attached contact plate against the outer edge of the respective angle bars, said means comprising a nut welded in the angle between the flanges and a bolt ex- 4 tending through said spreader bar and screwed into said nut.

5. In a driving core, a thrust bar of angle section having flanges, a contact plate, a spreader bar welded at its ends to said contact plate and having an opening, a nut welded in the angle between the flanges of the thrust bar, and a bolt extending through the opening in said spreader bar and screwed into said nut for drawing the edge of said contact plate against the outer edges of said flanges,

6. In an expandible driving core for a tubular shell, the combination of longitudinally disposed thrust bars spaced around a central axis, circumferentially arranged contact plates carried by said bars, an elastic expandible container supported between the thrust bars, and a nonmetallic, resilient wrapper interposed between said container and said thrust bars for transmitting pressure from the container to said thrust bars and expanding said core.

7. An expandible driving core comprising, in combination, a plurality of longitudinally extending angle bars, diaphragm plates rigidly secured to said angle bars at intervals along the length thereof in a plane substantially perpendicular to the length thereof, said diaphragm plates having outer surfaces constituting segments of a cylinder, and contact plates connected to said angle bars between said diaphragm plates, the outer surfaces of said contact plates extending in substantially a common cylindrical plane with the outer surfaces of said diaphragm plates.

8. In an expandible core according to claim 7, said contact plates being connected to said angle bars by means providing detachment, and said contact plates extending for substantially the entire distance between diaphragm plates, whereby said diaphragm plates constitute positioning means for said contact plates during the operation of attachment.

9. In a pneumatically expandible core for driving pile shells, the combination with a plurality of longitudinally extending angle bars, contact plates attached to said bars and an elastic container for pressure fluid, said container being located along a central axis and said bars being symmetrically disposed around said axis, of a non-metallic transmitting wrapper surrounding said container and contacting said bars, said wrapper being flexible and resilient whereby said core may be used with shells of various diameter.

10. In a core according to claim 9, said wrapper lcomprising alternate layers of nylon and rub- 11. In a core according to claim 10, the inner and outer layers of said wrapper being rubber and the nylon layers being woven,'and the entire wrapper being laminated.

WALTER H. COBI.

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date 1,164,435 Wallett Dec. 14, 1915 1,258,482 Shuman Mar. 5, 1918 1,491,832 Upson Apr. 29, 1924 2,313,625 Cobi Mar, 9, 1943 2,437,043 Riemenschneider et 91. Mar. 2, 1948 

